Valve for core drills



J. H. HOWARD Y 2,109,903

VALVE FOR CORE DRLL K March l, 1938.

'Filed Jan. 2e. 1957 Patented Mu. 1, `was UNITED "STATES Plrl'elvr OFFICE 9Claims.

' This invention relates to weil drilling tools and relates more particularly to a valve for a core drill for use in thel rotary method of well drilling. A general object of this invention is to provide a simple, practical valve for the upper end of the core-receiving barrel of a core drill that prevents the entrance of thick mud into the barrel whenv as it is displaced by the core. The typical form of core drill valve now in general use is a simple ball check valve having 'a ball that seats downwardly to prevent the entrance 'of the circulation 2 iiuid to the barrel and` that is adapted to open the circulation fluid. When a core drill equipped with a typical ball type check valve is run into a well, the valve opens due to the velocity of uid 2 iiow into the drilling string and thus allows` the rel and often clogs the barrel so that it is impossible to obtain a core. Valves have been in- ,l the drill after the' mud, etc. has been iiushed from the barrel by waterpumped downwardly through the drilling string. Thisvdrop-ball type of valve is satisfactory in many instances but cannot be employed where oat valves are connected in the drilling string, as such float valves prevent the ball from passing downwardly through the string to the drill. Another object of this invention is to provide a` valve for a core drill that closes when the drill is run into the well and, therefore, prevents mud, etc. from entering the core barrel.

Another object of this invention is to provide a valve for a core drill that may allow the light or clean fluid in the upper portion of the well to enter the barrel, but which remains closed as the drill approaches the bottom of .the well, thereby preventing heavy mud in the bottom of the well from entering and clogging the barrel.

` Another object of this invention is to provide a core drill valve of the character mentioned that remains closed during the making up of the joints in the drilling string as the string is being run into the well. l

l Another object of this invention is to provide a that will allow the fluid to escape from the barrel when the pressure in the barrel exceeds that of well iiuid to enter the barrel. If the mud at the. bottom of the bore is very thick it enters the bartroduced embodying a ball that is dropped into (CL Z55-72) core drill valve that automatically closes when the fluid is circulated through the drilling string preparatory to the drilling operation and that remains closed during the drilling operation to prevent the circulation fluid from washing away the core, vbut may open to allow the escape of fluid displaced from the barrel by the entering core.

Another object of this invention is to provide K a core drill valve of the character mentioned that is entirely automaticin'operation and that does not necessitate the dropping of an object through the drilling string and, therefore, is adapted for use in tools operated on a drilling string having float valves.

Another object of this invention is to provide a core drill valve of the character mentioned embodying novel dependable means for holding its parts properly assembled and tightly secured t the inner barrel.

A further object of this invention is to provide a core drill valve o f the character mentioned that is'simple, and inexpensive to manufacture, install and service.

The various objects and features of my invention will be fully understood from. the following detailed description of a typical, preferred form ofthe invention, throughout which description lreference is made to the accompanying drawing,

valve of the present invention on the inner barrel. Fig. 2 is a longitudinal detailed sectional view of the valve, taken substantially as indi cated by lines 2--2 on Fig. 3 and Figs. 3 and 4 are transverse detailed sectional views taken as indicated by lines 3-3 and li--4 on Fig. 2.

The improved valve provided by this invention is adapted to be embodied in or applied to core drills of various types and makes. In the following detailed disclosure I will describe one typical form'of the invention as used in connection with a more or less conventional rotary core drill. It is to be understood that the invention is not to be `construed as limited or restricted to the specic application of the invention illustrated in the drawing. i

The core drill illustrated in the drawing `in cludes an outer barrel l0 `to be connected with the lower end of a tubular well drilling string. A sub l I is provided on the upper end of the outer barrel I0 to facilitate its connection with the drilling string. A sub l2 is connected with the lower end of the outer barrel I0 and carries a annular uid space in the outer barrel.

cutter head I3. The cutter head I3 is provided with cutting means for making an annular cut in the earth formation. The particular headillustrated has spaced drag type blades I4 operable to make an annular cut in the formation and leave a core for reception by the drill. An inner barrel I5 is arranged longitudinally in the outer barrel I to receive the core. A collar I6 on the lower end of the inner barrel I cooperates with a recess in the head I3 to support the inner barrel. 'Ihe inner barrel I5 extends through the outer barrel Ill with substantial clearance leaving an Ports II in the collar I6 connect this fluid space with discharge ports I8 in the head I3. A core catcher I9 is provided in the head I3 to grip and retain the core. The blades I4 cut or leave the upstanding core which is received in the barrel I5 as the drilling progresses. The core catcher I9 is operable to break loose the core and to retain the core in the barrel I5 when the drill is removed from the well.

The improved valve of the present invention includes, generally, a body 20, means 2I for removably securing the body 20 to the upper end of the inner barrel I5, a cage 22 on the body 20, a valve seat 23 in the body 20 connected with the cage 22 and a valve or ball 24 in the cage 22.

The body 28 may be a simple tubular member as illustrated in the drawing. In practice the body 20 may be comparatively short and may have relatively thick walls. The tubular body 2li is adapted to enter the upper end of the inner barf rel I5, as will be more fully described. The opposite ends vof the body 22 may be flat and normal tov its; longitudinal axis.

flliea'neans` 2i for securing the body 20 to the inner barrel I5 is such that the valve may be .fea'sily `and quickly connected to and removed from the inner barrel. The means 2| includes a Lcoarse steeply pitched thread 25 on the body 20 r` matingwith a similar thread 26 on the barrel I5.

In'theconstruction illustrated the inner barrel I5 has a tubular extension connected to its upper end y 5ol I place.

by welding at 2'I and this extension carries the thread 26. It is to be understood that the thread 28 may be formed on the barrel I5 and I will consider the above-mentioned extensionas a part or continuation of the inner barrel. The thread 25 is preferably an external thread for cooperating with an internal thread 26 on the barrel I5. The threads 25 and 26 are steeply pitched so that the valve body 20 may be quickly threaded in The body 28 may have a downwardly facing external shoulder 28 for cooperating with the upper end of the inner barrel I5 to limit downward threading of the body.

The means 2l further includes a latch 29 for preventing unthreading of the body 20. The latch 29 is pivotauy supported by a pm an earned by' spaced lugs 3| on the upper endvof the body 20. The latch 29 projects downwardly and is partially received in a groove 32in the exterior of the body 20. The lower portion of the latch 29 is received in a notch 33 in the upper end of the inner barrel I5. It will be apparent how the latch 29 cooperating with the notch 33 prevents turning and unthreading of the body 20. The surrounding and confining outer barrel I0 limits outward piv' oting of the latch 29. and may prevent therlatch from disengaging from the notch 33.

'I'he cage 22 houses or contains the valve member or ball 24 and in the form ofthe invention illustrated serves to carry the seat 23 and to guide and stabilize the upper portion of the inner bar-v rel I5. The cage 22 is a tubular member having its lower end in communication with thev inner barrel I5 and having its upper end in communication with the interior of the outer barrel I0 and the drilling string. The tubular cage 22 is' provided between its ends with a chamber 34 for containing the ball 24. A downwardly facing annular shoulder 35 is provided on the lower end of the cage 22 to seat downwardly against the upper end of the body 20. A reduced portion 36 is provided on the lower end of the cage 22 and ts downwardly into the upper portion of the tubular body 20. An annular internal iiange 31 is provided in the body 20 and is engaged by the lower end of the said portion 36. The chamber 34 in the cage 22 has closed sidewalls and is only Y open at its upper and lower ends.

ltrated the seat 38 is a tapered annular face on an internal restriction or flange 39 occurring at the upper end of the chamber .34. 'I'he side walls of the chamber 34 preferably converge upwardly to the seat 38 to guide the ball 24 to the seat. The opening in the tubular extension or portion 35 is suiiiciently large in diameter to allow the ball 24 to cooperatel with the seat 23, as illustrated in Figs. 1 and 2.

The cage. 22 is preferably provided with a plurality of circumferentially spaced wings or guide ribs 40. The ribs 48 project outwardly or radially from the cage 22 and have outer longitudinal edges'adjacent the inner wall of the outer barrel I0 to definitely limit working or tilting of the inner barrel I5. The ribs 40 operate to centralize and stabilize the upper portion of the inner barrel I5. The upper ends of the guide ribs 48 may be inclined downwardly and outwardly. In practice the ribs..40 may be integral with the cage 22. One of the ribs 40 is provided atf its lower end with an extension or lug 4I adapted to cooper ate with a notch `42 in the upper end of the body 20. 'I'he lug 4I cooperating with the notch 42 prevents relative rotation between the body 2|! and the cage 22. 'I'he lug 4I is retained in the notch 42 in the manner to be subsequently de The valve seat 23 is provided in the body 28 and the cage 22 and is engageable by the ball 24 when the ball seats downwardly to prevent the entrance of circulation uid into the core receiving barrel I5. The seat 23 may be a simple annular member or tubular member, as illustrated. In accordance with the invention the seat 23 is threaded' upwardly into the lower portion 36 of the cage22 to have its upper end adjacent the lower wall of the chamber 34. An outwardly projecting annular flange 43 is provided on the seat 23 to engage upwardly against the body flange 81. 'I'he flange. 43 is preferably provided on the lower end ofthe seat 23. It will be observed that the iiangr 43 engaging upwardly against the flange 31 holds .the cage downwardly against the body 2li and, therefore, holds the lug"4|'in the-notch 42. The upper end of the aioaeos scribed above, so that the entire assembly is locked' 'against disconnection and loosening. f

The ball 2t may be a plain cylindrical member, as illustrated in the drawing. The ball 2d is proportioned to properly cooperate with the seat dit and the surface il@ of the seat 23. The ball 2t is movable through the chamber 3d with substantial clearance to permit fluid flow through the chamber when it is unseated from the seats t@ and 23. The ball 2d may be a solid metal member. However, it may be hollow or formed of a material of relatively low specific gravity to m'ore readily rise against the seat 38 with fluid flowing upwardly through the chamber at.

In operation the core drill is connected with the lower end of a tubular well drilling string and is run into the well on the lower end of the string. The well bore is usually iilled or substantially filled withy the rotary mud employ i. n the rotary method of well drilling. When the drill is run downwardly into the well the drilling string is, of

course, empty and the uid in the well ows upwardly through the inner barrel i5 and through the portsx id and il to pass through the outer barrel it. The fluid passing upwardly into the inner barrel i5 rushes through the cage 22 at a3 substantial velocity and raises the ball 2d so that it seats upwardly against the seat 3d. The ball 2d engaging upwardly against the seat 38 of course prevents further ilow through the cage 22 and thus prevents the further, entrance of uicl into the inner barrel `l 5. It will be apparent that the fluid received in the inner barrel l5 prior to closing of the' valve 2t is the fluid in the upper portion oil thel well bore. The fluid standing in the upper portion of the well bore is light and carries a minimum of solidmatter in suspension as such solid matter tends to settle inthe well. Thus the inner barrel i5 is occupied by clean and relativelylight fluid or liquid.

The ball 2d remains closed against the seat 3d as the drill is run through the bore to its lower'end.` In running a drilling string into a well it is necessary to connect or make up threaded connections-in the string.I During these operations the drilling string does not move downwardly. However, the column of fluid standing in the well around the outer barrel ld and the drilling string is higher than the column Vof fluid in the string so that a differential in pressure exists which maintains the ball 2d upwardly against the seat 3d. Accordingly, the ball 2d remains in cooperation with the seat 3E during the running of the tool into the well. When the core drill approaches the lower endof the well bore occupied by the heavy thick mud this mud is prevented from entering the inner barrel l5 by the relatively light and clean iiuid completely occupying the inner barrel. l

When the drill is in position at the bottom of the welll the circulation uid is pumped downwardly through the drilling string to discharge from the core drill.

This downwardly owing circulation fluid flows through the outer barrel I@ course, tends to flow downwardly through the cage 22 and the -inner barrel i5. The uid thus pumped downwardly through the drill moves the ball 2t downwardly against the seat surface td. The ball 2d engaging the seat surface ld prevents the downward ilow of circulation iluid into the inner barrel it. Thus the' bali 2t prevents the circulation uid from entering the inner barrel to wash away the core as the core is received in the inner barrel it. When the `upstanding core enters theinne'r barrel I5 it tends to displace the' fluid upwardly from the inner barrel. When the pressure on the fluid in the inner barrel becomes greater than the pressure on the circulation fluid the ball 2d raises from the seat surface M and permits'the escape of the trapped iuid from the inner barrel iii. As described above, the fluid trapped in the inner barrel i5 is a light, relatively clean'uid and does not interfere with the free entrance of the core to the barrel i5.

The core` drill valve provided by the invention operates to prevent the entrance of thick, heavy mud into the core receiving barrel when the drill is run into the well. This is important as it prevents such heavy mud from clogging the inner barrel to interfere with the reception of the core. The valve is also effective in preventing the downwardly flowing circulation uid from entering the inner barrel to Awash "away the core. The bod-y 2t of the valve may be easily and quickly threaded onto the inner barrel i and is dependably locked in place by the latch 29. The removable cage 22 and the releasable seat 23 are securely lato-hed or locked to the body 2li by the lugdi and the bar dt and cannot becomedisplaced. The seat 23 and the cage 22 may be readily'replaced when worn. The valve is easy to install and is dependable in operation.

' Having described only a typical preferred form and application of my invention, I do not wish to be limited or restricted to the specific details herein set forth, but wish yto reserve to myself any variations or modifications that may appear to those skilled in the art or fall within the scope I barrel, the combination of, a cage structure on the l upper end of the barrel having a chamber, valve seats at the upper and lower ends of the chamber, the wall of the chamber being inclined upwardly and inwardly toward the seat at the upper end of the chamber, and a movable valve member in the chamber for cooperating with the seats.

2. In a well core drill having a core receiving barrel, the combination of, a body, steep threads connecting the body with the barrel, latch means preventing unthreading of the body, a cage on the body, and means controlling fluid ow through the cage.

3. A valve for use on the core receiving barrel of a well core drill including, a body connected with the upper end of the barrel, the body having a notch, a cage seating on the body, a part on the cage cooperating with the notch, means holding the cage against the body, and a valve member in the cage controlling fluid ow therethrough. v y

4. A valve for use on the core receiving barrel of a well core drill including, a body connected with the upper end of the barrel, the body having a notch, a cage seating on the body, a part on the cage cooperating with the notch, means holding the cage against the body, a seat threaded in the cage, e. non-rotatable connection between the seat and the body, and a. valve member in the cage for cooperating with the seat.

5. A valve for use on the core receiving borrel of o. weil core drill including, a body connected with the upper end of the barrel. the body having a. notch, a. cage on the body leaving o. multiplicity o1 external ribs, one of solo ribs cooperating with the notch, a seat threaded to the coge, o nonrotatabie connection between the :seat and the body, end a valve in the cage moei-ating with the sect.

6. A valve for me on the core receiving barrel of o, well core drill including, n body connected with the upper end oi the barrel, the body having a notch, a. cage on the body having o. lug cooperatlng with the notch, a seat threaded to the cage end cooperating with the body to hold the cage where the lug is in the notch, menne goreventing unthreading of the sent, end o. ball in the cage for cooperating with the seat.

7. A valve for use on the core receiving leerrel of a Well core drill including. s. body connected With the upper end of the barrel, the bodyhaving a notch, a cage on the body having e lug cooperating with the notch, e seat threaded to thecage and cooperating with the body to hold the cage where the lug is in the notch, the seat heving o notch, a. bar secured to the body and cooperating'with the notch in the seat to prevent unthreading of the seat, and a. ball in the cage for cooperating with the seat.

8. A vai-'1e for use on the core receiving barrel of a well core drill including, a body connected with the upper end oi the borrel, the body having o. notch, e. cage on the bony having e. lug cooperating with the notch, o. seat tinenoed to tlie coge and cooperetim;f with the body to hold the coge where the lug is in the notch, a second seat in the coge spaced above and opposing the Erst mentioned seat, a ball in the cage for cooperating with the seats, and means preventing un threading of the first mentioned neat.

9. in n well core drill having a core receiving barrel, the combination of, o. tubular valve coge bovino an upwardly end inwardlyv inclined side woll, means removably securing the cage to the said barrel, vnlve seats at the upper and lower ends oi the coge, one oi' said sects being remov elaie, and a. ball in the cage operable to cooperate with the seats, said inclined side well guiding the.

bell lto the upper seat.

JOHN E. HOWARD. 

